SEAT: Satellite Era Accumulation Traverse: IceBridge Retraces 2010 SEAT traverse routeNovember 10th, 2011 by Maria-Jose Viñas
By Lora Koenig
Yesterday was an exciting day in the office. While I was downloading satellite data, answering e-mails and tying up loose ends before leaving for Antarctica, I was also closely following the NASA Airborne Sciences Flight Tracker and the flight path of the NASA DC-8 aircraft. The DC-8 is currently flying over Antarctica as part of the Operation IceBridge mission and yesterday it overflew the 2010 SEAT traverse line and ice core drilling sites. (For more detailed info on Operation IceBridge, check out the mission’s website).
I spent part of the day yesterday watching my screen as the flight tracker showed a little green aircraft moving over our 2010 route. Here is the aircraft approaching our line at about 1:40 PM Eastern time. (The tracker was not updating the plane image at this time, but the aircraft was at the end of the red line.)
Here it is halfway through. (Note that the plane does a 270-degree turn to line up on our traverse line to make sure it is leveled as it crosses our 2010 ice core sites. This ensures the best quality of radar data.)
And here is the plane at about 2:35 PM EST, finishing the portion of its flight that retraced our traverse and four ice core locations:
I watched on my screen as the IceBridge plane covered in just less than an hour the same ground that took us 12 days to cover last year.
OK, so I guess you are asking yourself: Why do we go out in the field, in sub-freezing weather, to drive around on snowmobiles for 12 days to do what a plane can do in an hour? Because you can not drill an ice core from an airplane. The airplane carries radars, which provide great spatial coverage of radar data, but we need to calibrate the radar data with the annual cycles we get from ice cores. (See last week’s blog post on how we determine annual cycles in the lab). So, yesterday, IceBridge collected great radar data that will compare to the data from our ice core sites, as well as to data from the WAIS divide ice core and the ice cores collected by a group led by Dr. Ian Joughin at University of Washington.
The IceBridge DC-8 aircraft flies with radars that are nearly identical to the ones we use on the ground. They are named Snow Radar and Ku-band Radar and are built by the Center for Remote Sensing of Ice Sheets, CReSIS. We will use the airborne radar data gathered yesterday to investigate any differences between what the radars are measuring from the air and on the ground.
In a week, we board our flights to Antarctica. After watching the IceBridge plane flying in West Antarctica yesterday, I am even more excited to get my boots on the ice.